What is Fatigue Damage Spectrum?
Fatigue Damage Spectrum is random vibration spectrum based on Miner’s Rule of Damage. Miner’s Rule teaches that fatigue damage will accumulate over time until it reaches a level that causes a crack or other deformation of a product.
Time Domain Calculation
Calculation through time domain, not frequency domain, to account for kurtosis you will likely see in the real world. The Fatigue Damage Spectrum is based on the response of single degree of freedom systems rather than FFTs.
Display Imported File Statistics
Displays peak acceleration, velocity, displacement as well as the kurtosis of the time history file. This provides a quick and easy way to determine the statistics of a waveform.
Configurable Process Parameters
The user can define the slope of the s/n curve (beta) and quality factor (Q).
Reduce Test Time
User sets test item target life based on product specifications, as well as test duration. The software automatically calculates ratios that will produce the same amount of fatigue damage in a user-defined test duration.
Analysis to Control
With one mouse click, begin controlling the newly created test profile on a shaker system all within VibrationVIEW. Go from a time waveform to a breakpoint profile and start controlling on that profile all in one program.
Calculate the combined fatigue of multiple weighted waveforms. Easily overlay and compare multiple waveforms on a single plot.
Includes Random Import (VR9204)
Compare multiple methods of generating a random profile.
FDS Technical Papers and Presentations (PDF)
FDS Video Demonstrations
Video 1 of 3
In this video we take field data collected from an engine run up and review it in VibrationVIEW software. The recorded waveform is opened and played back to analyze both the waveform and spectrum during the engine run up. Analyzing the data is the first step in producing a fatigue curve.
Video 2 of 3
In this video we transform the recorded data into a random power spectral density curve and make a direct comparison between the classic method using the “average” method followed by our new Fatigue Damage Spectrum method. Kurtosis is also measured and considered in the FDS transformation.
Video 3 of 3
In this video we use our FDS feature to address the age-old question of “is random or sine testing more severe?”. This question was addressed several years ago in one of our technical articles where a user asked “given both a sine test and a random test, how can I determine which is the more severe test”.
Comparing Ford Mustang Road Data Using the Fatigue Damage Spectrum (FDS) option
Mustang Comparison Project Description
Red Mustang Damage Calculation
Green Mustang Damage Calculation
Export Damage Data to Excel
Graph Excel Data
Ford Motor Case Study General Motors Case Study